Letro Letro | Universität Greifswald (original) (raw)

Papers by Letro Letro

Bhutan Journal of Natural Resources and Development

Natural habitats of Paphiopedilum fairrieanum (Lindl.) Stein was studied in the Taksha Range, Jig... more Natural habitats of Paphiopedilum fairrieanum (Lindl.) Stein was studied in the Taksha Range, Jigme Singye Wangchuck National Park, Bhutan, to determine the distribution range, population status, ecological conditions, and associated risks of the orchid. A total of 22 quadrat plots were assessed at two different locations at Rukha and Passang Omchu. The study discovered 519 individuals, mostly on steep slopes and cliffs in chirpine dominated forests with a canopy cover of less than 35% at elevations ranging from 980-1540 m above sea level. The plants were found on a limestone substrate with soil pH ranging from 7.3 to 8.0 and soil moisture content ranging from 1.4 to 2.5%, regardless of aspects and inclination. The greatest threats to the species in the study area were forest fire, browsing by wild ungulates, and anthropogenic activities.

Journal of Natural Resources, 2020

Journal of Threatened Taxa, 2021

We report the second photographic evidence of Temminck’s Tragopan Tragopan temminckii from Bhutan... more We report the second photographic evidence of Temminck’s Tragopan Tragopan temminckii from Bhutan. Inhabiting warm broadleaved forest at an elevation of 2,952m, the species photo captured in a camera trap was much westward than its previous record, indicating westward range expansion of this rare and elusive bird.

Bhutan Journal of Natural Resources and Development, 2020

We report a record of a threatened tortoise species, Indotestudo elongata, in a cool broad-leaved... more We report a record of a threatened tortoise species, Indotestudo elongata, in a cool broad-leaved forest in central Bhutan at high elevation. The tortoise was observed at an elevation of 1910 m asl, which is the highest elevation at which the species is recorded so far. This gives us an inference that this Critically Endangered species is now adapting to cooler regions at higher elevation.

This report presents the findings from two consecutive monitoring surveys (2016-2017 (2017), and ... more This report presents the findings from two consecutive monitoring surveys (2016-2017 (2017), and 2017-2018 (2018)). We report the number of tiger individuals captured in JSWNP during the two surveys, the diversity of wild felids and its sympatry with tigers, and occupancy and habitat use estimates of tiger and its prey species in the national park. We used remotely triggered camera traps to photo capture tigers of JSWNP in the potential tiger habitats. We established 39 camera stations during the first monitoring and 41 stations during the second monitoring session, with each camera trap functioning at least 60 days, over a total of 2617 and 2819 camera trap days respectively.

Nature Conservation Research

We assessed the human-bear interactions and distribution patterns of the Asiatic black bear Ursus... more We assessed the human-bear interactions and distribution patterns of the Asiatic black bear Ursus thibetanus in Jigme Singye Wangchuck National Park (JSWNP) in Bhutan through a questionnaire survey of park residents and by remote camera trapping. Our study revealed 26% (N = 311) of the respondents experiencing one or another form of human-bear interaction. Crop damage accounted for the highest interaction rate at 65%, followed by livestock depredation (25%), between 2012 and 2016. About 10% of the interactions involved human mual-bout 10% of the interactions involved human mualing cases in 2006-2016. About 80% of the respondents expressed support for bear conservation influenced mainly by conservation awareness programmes. Observations from 39 camera trap stations across the national park indicated a wide distribution of Asiatic black bears in JSWNP, with a mean site use probability of 0.55 (SE = 0.10, N = 39). With emerging perceived threats such as habitat fragmentation and loss, retaliatory killing, and poaching, it is recommended that the national park management adopt conservation measures that will enable a harmonious coexistence between humans and bears. Habitat enrichment with natural food resources for the bear, equipping communities with conflict preventive measures, and advocating local people on bear conservation are some of the measures that need to be adopted in the national park.

Monpas are aboriginal Bhutanese who inhabited the forests around Black Mountains in Bhutan. They ... more Monpas are aboriginal Bhutanese who inhabited the forests around Black Mountains in Bhutan. They lived their lives gathering food and materials from the forests, however, their livelihood activities are now shifting towards modern economy with coming of new settlements. A semi-structured questionnaire was administered for three Monpa villages within the administrative boundary of the Jigme Singye Wangchuck National Park in Bhutan. Modern education came very recently to the communities of Monpa and they still depend widely on agriculture, arts and crafts and on livestock farming. Such a practice of livelihood activities forms a perfect platform for conflict between the conservationist and communities. Recognizing the importance of communities in conservation efforts, Royal Government of Bhutan prioritized developmental initiatives for Monpas. Many Integrated Conservation Development Programs were initiated by the park to address some of the social issues and to garner support from co...

Journal of Threatened Taxa, 2021

Wildlife Research, 2020

Context. An effective management of human–wildlife conflict is key to successful conservation, es... more Context. An effective management of human–wildlife conflict is key to successful conservation, especially in areas where large carnivores occur. This is particularly important when new conservation regimes such as biological corridors are to be operationalised, as is the case in Bhutan. Aims. The aim of the study was to determine livestock depredation by tigers in a biological corridor (BC) in Bhutan and to assess the people’s perception towards tiger conservation and BC management. Methods. A semi-structured questionnaire survey with both open- and closed-ended questions was administered to 91 households from 10 villages. Chi-square tests were used to determine the association between predictor and response variables and multivariate logistic regressions to determine factors affecting the attitude of people towards conservation. Key results. Livestock losses were common, with 69% of respondents losing one or more livestock to predators between 2016 and 2018. Tigers were responsible...

Journal of Threatened Taxa, 2021

SUPPLEMENTARY TABLE 1 Results of goodness-of-fit tests for determining the optimal number of trap... more SUPPLEMENTARY TABLE 1 Results of goodness-of-fit tests for determining the optimal number of trapping days per species. The table shows the 2 probability (2) and overdispersion statistics (ĉ) of the goodness-of-fit tests (MacKenzie & Bailey, 2004) for principal prey species occupancy models with different collapsing periods (no. of days per sampling period). The collapsing periods with the overdispersion statistics (ĉ) closest to 1 are marked with * and were used for analysis.

Journal of Threatened Taxa, Oct 26, 2018

and is also the park focal for SMART patrolling. He is an active field biologists with deep taxon... more and is also the park focal for SMART patrolling. He is an active field biologists with deep taxonomical knowledge in flora and fauna. Limited experts in the herpetological field in Bhutan made Tshewang put special interests in herpetofauna. Letro Letro serves as a Forestry Officer at Jigme Singye Wangchuck National Park and coordinates various conservation research works in the park. Currently he is a graduate student at the University of Greifswald, studying Landscape Ecology and Nature Conservation. His research focuses on landscape approach conservation of wildlife. Author Contribution: ST organized the field survey works, collected the data, identified the species, and drafted the paper. LL conceptualized the research work, analysed the data, and wrote the paper. Acknowledgements: The study was executed as a part of WWF UK funded project "Intensive priority Conservation through Community participation for maintaining viable Biodiversity and Ecological Connectivity in B2C2 landscape", therefore we would like to thank WWF UK for funding the work and WWF Bhutan for their continued financial and technical support. We thank Mr.

Technical Report, 2019

Nature Conservation Research, 2020

We assessed the human-bear interactions and distribution patterns of the Asiatic black bear Ursus... more We assessed the human-bear interactions and distribution patterns of the Asiatic black bear Ursus thibetanus in Jigme Singye Wangchuck National Park (JSWNP) in Bhutan through a questionnaire survey of park residents and by remote camera trapping. Our study revealed 26% (N = 311) of the respondents experiencing one or another form of human-bear interaction. Crop damage accounted for the highest interaction rate at 65%, followed by livestock depredation (25%), between 2012 and 2016. About 10% of the interactions involved human mual-bout 10% of the interactions involved human mual-ing cases in 2006-2016. About 80% of the respondents expressed support for bear conservation influenced mainly by conservation awareness programmes. Observations from 39 camera trap stations across the national park indicated a wide distribution of Asiatic black bears in JSWNP, with a mean site use probability of 0.55 (SE = 0.10, N = 39). With emerging perceived threats such as habitat fragmentation and loss, retaliatory killing, and poaching, it is recommended that the national park management adopt conservation measures that will enable a harmonious coexistence between humans and bears. Habitat enrichment with natural food resources for the bear, equipping communities with conflict preventive measures, and advocating local people on bear conservation are some of the measures that need to be adopted in the national park.

Journal of Insect Behaviour, 2018

Habitat loss and anthropogenic climate change are important threats to biodiversity conservation.... more Habitat loss and anthropogenic climate change are important threats to biodiversity conservation. Owing to the concomitantly deteriorating habitat quality, individuals are often forced to disperse to new habitats, rendering dispersal an ecologically important process. However, dispersal ability may differ within and among populations, and is further dependent on environmental conditions. We therefore studied sexual differences in and environmental effects on movement patterns in the sooty copper butterfly Lycaena tityrus. As predicted, males were more active and covered longer distances than females, presumably owing to mate location and territorial disputes. Males alighted more often on flowers than females, probably to fuel their high flight activity, while females showed a high affinity to host-plants for egg-laying. Our findings provide a striking example of sex-related differences in animal behavior, as revealed by the use of customary smartphones, which apparently can comprise suitable means to reveal biologically significant behav-ioural patterns. More problematic than the technical device used seems to be the challenge of following individual butterflies for long enough in the field, such that any extrapola-tions to dispersal seem difficult.

The user has requested enhancement of the downloaded file. All in-text references underlined in b... more The user has requested enhancement of the downloaded file. All in-text references underlined in blue are added to the original document and are linked to publications on ResearchGate, letting you access and read them immediately.

This study was carried out in Jigme Singye Wangchuck National Park, Bhutan in 2013 to generate in... more This study was carried out in Jigme Singye Wangchuck National Park, Bhutan in 2013 to generate information on cattle husbandry and human-wildlife interactions in the park. A majority of the people interviewed owned livestock and they reported sufficient grazing grounds. However, livestock depredations had occurred frequently in the last three years from the date of interview and many went unreported. From those who did, very few got compensated. Retaliatory killing is seen as one of the significant threat to wildlife inside the park. We recommend cooperation between rural farmers and the wildlife managers to come up with more realistic mitigation measures to lessen the conflict. Proper herd management practices and institution of viable and sustainable insurance schemes could be few of the ways which can alleviate the issue.

The study on pasture and grazing in JSWNP is conducted to establish the extent of grazing area in... more The study on pasture and grazing in JSWNP is conducted to establish the extent of grazing area in the national park while also attempting to understand the practice of migratory cattle grazing and its impact on forests.
The study is carried out in two phases. The first was aimed at ascertaining the residential cattle population in the park, their grazing behaviour and the threats like predation. The second phase focused on the migratory cattle herders from outside the park and their seasonal grazing habit. It also attempted to map the pasturelands in the park.
The JSWNP spans over eleven geogs of five districts. Livestock rearing is an occupation almost all the park residents adopt, besides farming. While most farmers in the park area own a few cattle heads and do not practice seasonal migration, those from Retey village under Jigme Choeling geog are agro-pastoral farmers rearing huge number of cattle heads. It was learnt that about eight households rear over 300 cattle heads in a traditional migratory system.
The subtropical forests of the JSWNP, since ancient times, served as pastureland for the migratory cattle herders from far-flung villages, including Bumthang. Most of the pasturelands are found in Langthel, Nabji and Tingtibi range. In Nabji range, about six households from Bumthang rear their cattle there. Three households occupy Langthel and five more are in Tingtibi range.
Migration takes place to warmer, southern regions during winter. The cattle that migrate to the park are largely from Chumey geog in Bumthang to Langthel and Korphu geogs in Trongsa, Trong geog in Zhemgang and Jigmechoeling geog in Sarpang. Besides, there are certain herds of yak that graze in alpine region of the national park during summer. These are inter-migration in altitudinal movement from a dzongkhag to another (Bumthang to Trongsa, Zhemgang, Sarpang, Wangdue to Trongsa). Intramigration within the dzongkhag, from a geog to another is also prevalent. (Tangsibji to Langthel, Drakteng to Tangsibji). An approximate area of 348 kilometre-square is found to be covered be migratory cattle.
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While the overall trend in cattle migration is gradually dwindling in terms of number of herds as well as cattle population, it is still prevalent in Chumey geog in Bumthang, Jigmechoeling geog (Retey village) in Sarpang and Phobji geog in Wangduephodrang. For these migratory herders, livestock is the major occupation and the only source of income.
The zonation report of the national park has designated 767.03 kilometre square (44.52 percent of the total park area) as multiple use zone, within which are the park residents and their resource extraction areas. It is also under this zone that the pastures of the cattle herders are found. Unlike in the past where individuals owned the pasturelands (tsamdrogs), government today has taken charge in keeping with the Land Act, 2007. These pasturelands are government plots in town areas while it has been reverted to Government Reserved Forest in rural areas. In JSWNP, most of the tsamdrogs belong to residents of Bumthang who have grazing rights during winters. There are about 14 households who use the park for at least six winter months for the over 1,160 cattle heads they own. The legislations protect property rights over pastures. The range lands become the asset of the nation where herdsmen only have the usufruct rights.
The bulk of cattle in the park still comprise local breeds. Except for a few villages where rearing crossbreeds are common, all the resident and migratory cattle are local. This also means the impact of grazing is going to be adverse with many soil trampling incidences, excessive browsing, increased number of depredation, etc. Therefore, JSWNP should put efforts to explore options to encourage rearing improved breeds to reduce rearing non-productive cattle. It would also be a good idea to develop backyard dairy units. Such initiative will increase dairy products, raise income and reduce grazing pressure on forests.
The study conducted shows that grazing in the broadleaved forests has altered the composition of forest species because of excessive browsing of palatable species, leaving unpalatable ones in abundance.
There are little evidences of lopping and felling fresh trees for fuel wood though cutting pole-sized trees are common for erecting temporary sheds. The practice of rotational grazing, where they spend short duration in each transit camp, is believed to have adverse impact on the ecosystem.
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Since migratory grazing is a tradition and practice of tsamdrogs are their traditional rights, it is often difficult for the park management to address the problems of imperceptible degradation of biodiversity. The temperate and sub-tropical areas in JSWNP are grazed throughout the season by the migratory and resident cattle while yaks scrape the alpine areas. The present intervention of park zoning would help reduce opening more forests for grazing. Regular awareness campaign among park residents as well as the migratory cattle herders would help curb the problem of excessive grazing.
However, the number of cattle as well as cattle herders, as per the local information, has declined over the years and in the near future, there are chances of cattle migration practice coming to an end. While excessive grazing would be hazardous, certain degree of grazing is considered necessary for better ecosystem health.
Community-based eco-tourism should be introduced in the park using migratory trails as trekking routes with involvement of local communities. Eco-tourism would bring tourists to rural areas and benefit local people from guiding the tourists, providing porter/pony, sparing rooms for guests, selling local dishes and handicrafts. Such livelihoods with enhanced economic opportunities in the rural areas will minimize migration of both cattle and people, thereby improving the living standards of the rural people.

Bhutan Journal of Natural Resources and Development

Journal of Natural Resources, 2020

Journal of Threatened Taxa, 2021

Bhutan Journal of Natural Resources and Development, 2020

Nature Conservation Research

Journal of Threatened Taxa, 2021

Wildlife Research, 2020

Journal of Threatened Taxa, 2021

Journal of Threatened Taxa, Oct 26, 2018

Technical Report, 2019

Nature Conservation Research, 2020

We assessed the human-bear interactions and distribution patterns of the Asiatic black bear Ursus... more We assessed the human-bear interactions and distribution patterns of the Asiatic black bear Ursus thibetanus in Jigme Singye Wangchuck National Park (JSWNP) in Bhutan through a questionnaire survey of park residents and by remote camera trapping. Our study revealed 26% (N = 311) of the respondents experiencing one or another form of human-bear interaction. Crop damage accounted for the highest interaction rate at 65%, followed by livestock depredation (25%), between 2012 and 2016. About 10% of the interactions involved human mual-bout 10% of the interactions involved human mual-ing cases in 2006-2016. About 80% of the respondents expressed support for bear conservation influenced mainly by conservation awareness programmes. Observations from 39 camera trap stations across the national park indicated a wide distribution of Asiatic black bears in JSWNP, with a mean site use probability of 0.55 (SE = 0.10, N = 39). With emerging perceived threats such as habitat fragmentation and loss, retaliatory killing, and poaching, it is recommended that the national park management adopt conservation measures that will enable a harmonious coexistence between humans and bears. Habitat enrichment with natural food resources for the bear, equipping communities with conflict preventive measures, and advocating local people on bear conservation are some of the measures that need to be adopted in the national park.

Journal of Insect Behaviour, 2018

This is prepared for a 10 minutes presentation work for course work in the University.

hutan’s strategic location in the biologically diverse Eastern Himalayas is endowed with pristine... more hutan’s strategic location in the biologically diverse Eastern Himalayas is endowed with pristine forest coverage. Guided by principles of Gross National Happiness, modern development is pursued through middle path approach without compromising environmental conservation. In the core are the protected areas that serve as home to many endangered wildlife, for which landscape approach conservation is vital. The biological corridors link the numerous protected areas enabling successful landscape conservation. However, many anthropogenic factors pose challenge to its management, and current road widening projects deteriorated the conditions of the BC’s, risking its functionality. Will the strong environmental policies help restore them to its previous glory? Will the emerging discipline of restoration ecology provide a powerful suite of tools for speeding the recovery of degraded lands? An efficient restoration plan is vital for securing the purpose of the disturbed BCs.

Bhutan's strategic location in the biologically diverse Eastern Himalayas is endowed with pristin... more Bhutan's strategic location in the biologically diverse Eastern Himalayas is endowed with pristine forest coverage. Guided by principles of Gross National Happiness, modern development is pursued through middle path approach without compromising environmental conservation. In the core are the protected areas that serve as home to many endangered wildlife, for which landscape approach conservation is vital. The biological corridors link the numerous protected areas enabling successful landscape conservation. However, many anthropogenic factors pose challenge to its management, and current road widening projects deteriorated the conditions of the BC's, risking its functionality. Will the strong environmental policies help restore them to its previous glory? Will the emerging discipline of restoration ecology provide a powerful suite of tools for speeding the recovery of degraded lands? An efficient restoration plan is vital for securing the purpose of the disturbed BCs.